1. Field of the Invention
The subject invention relates to stencil making and utilization methods, apparatus and articles, to stencils and to screen printing and stenciling.
2. Disclosure Statement
The following disclosure statement is made pursuant to the duty of disclosure imposed by law and formulated in 37 CFR 1.56(a). No representation is hereby made that information thus disclosed in fact constitutes prior art, inasmuch as 37 CFR 1.56(a) relies on a materiality concept which depends on uncertain and inevitably subjective elements of substantial likelihood and reasonableness, and inasmuch as a growing attitude appears to require citation of material which might lead to a discovery of pertinent material though not necessarily being of itself pertinent. Also, the following comments contain conclusions and observations which have only been drawn or become apparent after conception of the subject invention or which contrast the subject invention or its merits against the background of developments which may be subsequent in time or priority.
A simple form of stencil comprises a thin sheet of paper, metal or another material, which is perforated or cut through in such a way that an application of ink, paint or another suitable substance to the stencil will producepatterns, designs or lettering corresponding to the perforation or cutout on a surface beneath the applied stencil.
The making of stencils requires special tools and skills which are generally beyond the reach of broad segments of the population and which, by their very nature, typically inhibit an expression of individual creativity on the part of the user. The same applies to other quality methods and devices for producing patterns, designs and letters by artisans, children and hobbyists or by others in relatively small series.
A special stencil printing method is known as silk screen printing or serigraphy, which is an ancient art, involving the printing of patterns, designs and lettering through a piece of silk or other fine cloth in which selected areas have been stopped out by an impermeable film.
Considerable progress has been realized in this art with the availability and use of photosensitive emulsions for selectively stopping areas of the screen upon photographic exposure and development. A further important step in the direction of a more general use of this enjoyable meaningful and useful art came about with the provision and availability of direct photo emulsions, typically of the diazo type, where the photographic development upon exposure is conveniently reduced for the user to a washout under subdued light, whereby the emulsion will be removed from non-stopped areas of the screen. For raised image printing plates, a special nylon screen has been sensitized with a dichromate.
My prior U.S. Pat. No. 4,142,464, issued Mar. 6, 1979 and herewith incorporated by reference herein, went a long way of relieving the state of the art of its makeshift nature at the amateur and user level, especially in the area or providing the desired image pattern and preparing the stencil by photographic methods.
A persistent problem with the use of photo emulsions is the light and temperature sensitivity and the naturally limited shelf life of the sensitized emulsions, requiring operation under darkroom conditions or with opaque packages and frequently necessitating refrigerated storage.
Even if manufacturers and users are willing and able to put up with these problems, they still are practically relegated to operation with clear film material to which the pattern, design or lettering to be printed has to be applied beforehand. While there are applications in which the latter procedure is still useful, artistic expression and ease of operation are impeded in many other areas.
There also has been a need for methods, apparatus and articles for producing durable and appealing designs and ornamentations on ceramics and various other objects without use of a kiln or other complex equipment.
There further has been a need for repairing and joining articles in a novel and durable manner.